Azo-dyestuffs and process of making same



Patented Aug. 11, 1936 Walter Anderau, Basel,

AND PROCESS OF Switzerland, assignor to the firm of Society of Chemical Industry in Basle, Basel, Switzerland I No Drawing. Application April 2, 1936, Serial No. 72,437. In Switzerland April 18, 1935 4 Claims.

"This invention consists in the manufacture of :azo-dystuffs by combining 2 mols. of a diazocompound of an amino-azo-dyestufi of the general formula Boss on; H

acids and, on the other hand, aniline, naphthylamines, aminophenols, aminonaphthols, alkoxyanilines, alkoxynaphthylamines, aminobenzenecarboxylic acids and aminonaphthalene-carboxylic acids; these bodies may contain further substituents, for instance halogen or nitroor alkyl-groups, such as methylor ethyl-groups. The coupling of the diazotized amino-azo-dyestuffs with 5,5dihydroxy-2,2'dinaphthylamine- 7,'7-disulfonic acid is performed in the usual manner in an alkaline medium; the alkalinity of the'medium may be due for instance to sodium carbonate, sodium bicarbonate or ammonia.

The dyestuffs obtainable by the invention dye cellulosic and vegetable fibers, such as cotton and. artificial silk from regenerated cellulose, blue tints; dyeings particularly valuable in respect of 45 their properties of fastness, especially fastness to washing are obtained by treating the dyeings with agents that yield metal, for instance chromium, coller, iron cobalt, nickel, manganese, ,zinc, vanadium or titanium.

HOaS

coon The following examples illustrate the invention the parts being by weight- Example 1 The amino-azo-compound from 153 parts of 4- amino-1hydroxy-benzene2-carboxylic acid and 5 137 parts of 1-amino2-methoxy-5-methylbenzone is diazotized by means of 250 parts of hydrochloric acid and 70 parts of sodium nitrite and the diazo-solution is coupled, in presence of 600 parts of sodium carbonate, with a solution of 462 parts of 5,5-dihydroxy-'7,7'-disulfo-2,2'-dinaphthylamine at 0 C. The whole is then further coupled with the diazo-compound of the aminoazo-cornpound, which is obtainable from 153 parts of 4amino-lhydroxybenzene-Z-carboxylic acid by coupling in acid solution with 153 parts of 1- amino-2,5dimethoxy-benzene.

The tetrakisazo-dyestuff thus formed. has the formula SOaH NH I com It is separated by addition of common salt. It dissolves in water and dilute alkalies to blue solutions and in concentrated sulfuric acid also to a blue solution. It dyes cotton or viscose in a bath containing sodium carbonate and Glaubers salt blue tints which become fast to light and washing after treatment with copper salts.

Example 2 S 03H NH O CH: O OH It is filtered and dried.

The dyestufi is a dark bronze powder, soluble in water and in dilute alkali to a blue solution and in concentrated sulfuric acid to a blue green solution. It dyes cellulosic fibres, such as cotton coon on and artificial silk from regenerated cellulose, in a bath containing sodium carbonate and Glaubers salt, blue tints. By after-treatment with copper salts the dyeings become fast to washing and to light without essential variation of the tint.

Example 3 154 parts of 4-amino--1-hydroxybenzene-2- c arboxyl ic acidare diazotized with 250 parts of hydrochloric acidand '70 parts of sodium nitrite and coupled in feebly acid solution with 137 parts of l-amino 2-methoxy-5-methylbenzene, the free mineral acid being buffered with sodium formate. The aminoazo-dyestuff thus formed is filtered, suspended in water and diazotized with 250 parts of hydrochloric acid and 70 parts of sodium nitrite. The diazo-c ompound is coupled in presence of 400 parts of sodium carbonate with a solution of 230 parts of 5,5-dihydroxyr'7,'7'-disulfo-2,2-dinaphthylamine. The whole is stirred for some time at -4 G. The dyestuff which has the formula 1103s CH3? 0 O OH 0113 is salted out, filtered and dried. It is then a blackish bronze powder, soluble in water and in dilute alkalies to a blue solution and in concentrated sulfuric acid to a green-blue solution. It dyes cotton and artificial silk from regenerated cellulose in a bath containing sodium carbonate and Glaubers salt blue tints which become thoroughly fast to light and washing by after-treatment with solutions of copper salts.

Example 4 154 parts of 4-amino-1-hydroxybenzene-2- carboxylicacid are diazotized and coupled in the presence of sodium acetate, that is to say in a faintly acid medium, with 143 parts of l-amino- HOa'S HOOC naphthalene. When coupling is 'finished the aminoazo-dyestuif thus formed'is isolated and dissolved in water with the aid of80 parts of caustic .soda. 70 parts of sodium nitrite are added and the solution is allowed to run into a mixtureof ice and hydrochloric acid, whereby diazotization occurs; it is completed after stirring for about 1 hour.

The diazonium compound thus obtained is coupled in the presence of sodium carbonate with 230 parts of 5,5-dihydroxy-7,'7-disulfo-2,2'-dinaphthylamine whereby there is formed a tetrakisazo-dyestuif which has the formula SOaH N=N N= Q01: n oon When coupling is finished the precipitation of the dyestuff is completed by addition of common salt and the dyestuff is filtered and dried. It is a blackish powder having a bronze lustre and is soluble in water and dilute alkalies to blue solutions and in concentrated sulfuric acid to a bluegr'en solution. It dyes cotton in a bath conradical R stand in ortho-position to one another,

.with 1 mole of 5,5'-dihydroxy-2,2'-dinaphthylamine-L'T-disulfonic acid.

2. Processfor'the manufacture of an azo-dyes'tulf, consisting in coupling 2 moles of the diazocompound of the aminoazo-dyestuff of the formula HO 0% C H:

with 1 mole f 5,5-dihydroxy-2,2-dinaphthylamine-7,7-disulfonic acid.

3. Azo-dyestuffs of the-general formula N=NR1'N- N-R a V wherein R. and. R1 represent unsulfonated arylene radicals selected from the group consisting of phenylene and naphthylene and wherein the OH-group and the carboxyl-group of the arylene radicalR. stand in ortho-position to\one another, which products are dark colored ipowders, dissolving in water and dilute alkalies to blue solutions, in concentrated sulfuric acid to blue to blue-green solutions, and dyeing vegetable fibers which product is a, dark colored powder, dissolvblue tints which when after-treated with coping in water and dilute alkalies to a. blue soluper compounds becomes fast to light and washtion, in concentrated sulfuric acid to a blueing. green solution, and dyeing vegetable fibers blue 5 4. The azo-dyestufi of the formula tints which when after-treated with copper 5 compounds become fast to light and washing. H018 SOzH mm NH I OCH:

00011 $01!: H OH OH; COOH WALTER ANDERAU'. 

